Among many spectral magnitude representations, we use (log-magnitude) CQT since the logarithmic frequency scale is known to match well to human auditory perception [1]}. We followed the implementation of Pseudo-CQThttp://librosa.github.io/librosa/
which multiplies linear-to-octave filterbanks to an STFT. As a result, the CQT covered nearly 8-octave bands from 32.07 Hz (C1) to 8 kHz (the Nyquist frequency of our experiment) with a 12-band/octave resolution. This implementation is differentiable.
